Songs you'll never forget, the film you've never seen and a story that's never been told. In August 1967, in the wake of the extraordinary impact of Sgt. Pepper's Lonely Hearts Club Band, The Beatles made a film. It was seen in the U.K. by a huge audience, at 8.35 p.m. on BBC One on Britain's Boxing Day...and all hell broke loose.

The story behind that film - Magical Mystery Tour - is revealed on Magical Mystery Tour Revisitedon THIRTEEN'S Great Performances, Friday, December 14 at 9 p.m. on PBS. (Check local listings.) The Beatles' Magical Mystery Tour itself will follow at 10 p.m. (Check local listings.)

Magical Mystery Tour was chock-full of thinly veiled references to psychedelia, anarchy and fantasy, all in the setting of a traditional British sightseeing bus outing to the seaside. This was a far cry from the innocent loveable mop-top japery of Help! and A Hard Day's Night.

Middle Britain had tuned in but was a long way from turning on and dropping out - the nation was baffled and outraged by the film's unexpected and uncompromising surreal, non-linear narrative. Paul McCartney appeared on The Frost Programme on rival ITV the day after transmission. He was called upon to account for himself and the rest of the group.

Could it be that a pearl was cast before swine and then thrown away? To its small band of admirers, it was a masterpiece of surreal British wit and imagination in the tradition of The Goons and Alice in Wonderland.

Now with the film fully restored to the highest technical standard with a remixed soundtrack, it's time to tell the extraordinary story of Magical Mystery Tour: why it was made, how it was made and the circumstances in which it was made. In the summer of 1967, The Beatles had the world at their feet. It's impossible to overestimate the effect of Sgt. Pepper's Lonely Hearts Club Band; that was revolutionary too but everyone loved it. In August, Brian Epstein tragically died, leaving the Beatles not only without a manager, but without their ambassador. They decided to go ahead with the film they'd been planning.

To tell the story, this film calls on those who were there, most notably Paul McCartney, who had the original idea, and Ringo Starr, who is credited as the director of photography. John Lennon and George Harrison are represented through interviews over the years and through their appearances in the film itself and in the copious and fascinating outtakes.